Evaluation of Polypyrrole as a Functional Sorbent for Water Treatment Technologies

Abstract

Featured Application: The information provided in the review can be valuable and interesting for a broad audience of scientists involved in the synthesis of modern polypyrrole-based materials, as well as the groups that utilize it as a component of nanocomposites aimed at a sorbent functional unit. The knowledge of the relation between the synthetic path and morphological parameters opens the possibility to use it in reverse technology and tailor materials of the future with enhanced sustainability and efficiency of usage. Polypyrrole, which belongs to the conducting polymer family, has demonstrated profound potential in advanced water purification applications due to its inherent electrical conductivity, environmental stability, and tunable surface chemistry. As a sorbent, PPy exhibits high sorption capacity for aquatic contaminants, including heavy metals, pharmaceutical compounds, and their metabolites, as well as synthetic dyes. The removal efficiency is correlated to a complex interaction mechanism involving electrostatic attractions, redox activity, and π–π stacking. Recent advances have expanded the utility by further developing nanostructured PPy-based (nano)composites, which elevate sorption performance by increasing surface area, mechanical integrity, and selective affinity. In addition, its integration into membrane technologies has enabled the design of an effective filtration system with improved selectivity and regeneration capabilities. Moreover, PPy is effective in electrochemical processes of water treatment, including capacitive deionization and electrochemically assisted sorption, opening novel paths towards energy-efficient pollutant removal. The multifunctionality of PPy as a sorbent material highlights its value as an important material for water treatment, with the capability of extended modification tailored for emerging environmental needs revised in this work.